A hydrogen line installed as part of upgrades to a cooling system in a Puerto Rico power station was found to be leaking from two pipe joints 600mm apart, requiring repair and reinforcement before the new system could go into service.

Case Study Overview

Site Power station
Location Puerto Rico
Pipe Type Hydrogen line
Repair Type Leaking joint repair
Products Superfast Steel Epoxy Putty, SylWrap Pipe Repair Bandage

Pipe Defect

The power station had previously procured and stored hydrogen in an off-site tank before transporting to the plant. This was an expensive and inefficient process.

Sometimes, the tank would lay empty for four days awaiting a delivery of hydrogen to refill it. This caused interruptions to power output as turbines at the plant had to be shut down when supply ran out.

To overcome this, the plant took the decision to install a new cooling system, including an on-site hydrogen generator capable of supplying gas as and when required.

A network of pipes were installed to carry hydrogen from the generator to the areas of the plant where it was needed for cooling purposes. This eliminated the need for the power station to buy and store gas away from the plant.

Prior to the new cooling system going into full service, the line was slightly pressurised before being tested for leaks using portable hydrogen detectors.

This was necessary as the small molecule size of hydrogen enables it to escape through the tiniest of gaps and cracks. Human senses cannot detect its presence as the gas is colourless, odourless and tasteless.

The inspection revealed one section of line to be leaking. Gas was suspected to be escaping from two joints between two valves 600mm apart.

Although the amount of hydrogen escaping did not pose a danger – nor was there much prospect of harmful levels accumulating – the plant decided to repair and reinforce the pipe.

SylWrap Solution

The line was isolated and Superfast Steel Epoxy Putty Stick applied to the joints at either end of the pipe. The required amount of putty was cut from the stick, kneaded by hand and pushed tightly onto the pipe around both joints whilst soft.

Within 10 minutes, the putty had hardened to form a steel-like material over the joints. This plugged any gaps through which hydrogen could be escaping, sealing the pipe.

A SylWrap Pipe Repair Bandage was then applied along the entire 600mm section, reinforcing the line. SylWrap Bandage was dipped in water to activate the resin and then wrapped around the pipe with a 50 percent overlay.

Effective wrapping was still possible despite the pipe being positioned close to a wall. Further water was used to smooth the bandage onto the pipe.

SylWrap began to harden in minutes and once cured, it provided a rock-hard, chemically inert outer sleeve encompassing the pipe to prevent further hydrogen molecules from escaping.

Outcome

24 hours after completing the repair and the line was repressurised. The system was again inspected using hydrogen detectors which this time could find no gas in the air, indicating that the application had been a success. The new cooling system was subsequently put into full service.

Follow Up

Several years later and there were still no signs of hydrogen escaping from the repaired pipe section. The power station meanwhile had saved thousands via their decision to generate their own hydrogen on site.

They remained grateful to Sylmasta for helping get the cooling system online quickly and effectively. The plant maintained a stock of SylWrap Standard Pipe Repair Kits in case of future degrading of the line and other pipes on-site, which could cause leaks.

Products Used

Superfast Steel
Fast working epoxy putty for filling gaps, holes and plugging leaking joints

SylWrap Pipe Repair Bandage
Water-activated wrap sets rock hard to reinforce, protect and strengthen pipes

Standard Pipe Repair Kit
Superfast Steel and SylWrap Bandage come together in a Standard Pipe Repair Kit

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